The Role of Depth and Flatness of a Potential Energy Surface in Chemical Reaction Dynamics
The Role of Depth and Flatness of a Potential Energy Surface in Chemical Reaction Dynamics
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势能面的深度和平坦度在化学反应动力学中的作用
DOI：
10.1134/s1560354720050044
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发表时间：
2020
影响因子：
1.4
通讯作者：
S. Wiggins
中科院分区：
文献类型：
--
作者：
Wenyang Lyu;Shibabrat Naik;S. Wiggins
在这项研究中，我们分析了势能面在深度和平坦度方面的几何变化如何影响反应动力学。我们在单自由度和二自由度哈密顿范式的背景下描述了鞍结分叉的深度和平坦度，并量化了它们对化学反应动力学的影响[1，2]。在最近的一项研究中，加西亚-加里多等人。[2]说明了改变势能面(PES)的井深如何导致鞍节分叉。他们展示了与秩为1的鞍点有关的圆柱流形的几何如何在到达鞍点分叉的过程中发生变化。利用这里提出的公式，我们展示了势能参数的变化如何控制深度和平坦度，并展示了它们在化学反应的定量测量中的作用。我们通过计算瓶颈宽度和势垒宽度的比率、反应几率(也称为跃迁分数或布居分数)、间隙时间(或首次通过时间)分布以及总能量从小到高的分割面的定向通量(DS)来量化深度和平坦度的作用。这些定量测量的结果与对反应动力学的定性认识是一致的。
In this study, we analyze how changes in the geometry of a potential energy surface in terms of depth and flatness can affect the reaction dynamics. We formulate depth and flatness in the context of one- and two-degree-of-freedom (DOF) Hamiltonian normal form for the saddle-node bifurcation and quantify their influence on chemical reaction dynamics [1, 2]. In a recent work, García-Garrido et al. [2] illustrated how changing the well-depth of a potential energy surface (PES) can lead to a saddle-node bifurcation. They have shown how the geometry of cylindrical manifolds associated with the rank-1 saddle changes en route to the saddle-node bifurcation. Using the formulation presented here, we show how changes in the parameters of the potential energy control the depth and flatness and show their role in the quantitative measures of a chemical reaction. We quantify this role of the depth and flatness by calculating the ratio of the bottleneck width and well width, reaction probability (also known as transition fraction or population fraction), gap time (or first passage time) distribution, and directional flux through the dividing surface (DS) for small to high values of total energy. The results obtained for these quantitative measures are in agreement with the qualitative understanding of the reaction dynamics.
影响因子：
2.4
作者：
Ross, Shane D.;BozorgMagham, Amir E.;Naik, Shibabrat;Virgin, Lawrence N.
通讯作者：
Virgin, Lawrence N.